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Animal and Plant Toxins
Published in Lorris G. Cockerham, Barbara S. Shane, Basic Environmental Toxicology, 2019
Jason S. Albertson, Frederick W. Oehme
Ergot (Claviceps spp.) is a parasitic fungus which attacks the developing ovary of the grass flower, especially rye grass. The parasitic fruiting body (the Sclerotium) replaces or invades the grass ovary. Growth of the fungus is promoted by warm, moist conditions. Three major groups of alkaloids produced by the ergot fungus are ergotamine, ergotoxine, and ergometrine. Ergot alkaloids enhance smooth muscle contraction causing constriction of blood vessels and the muscles of the female reproductive tract. The toxicity of ergot is usually characterized by necrosis and gangrene of the extremities, mimicking frostbite. Ergot alkaloids also inhibit prolactin secretion, resulting in noninflammatory agalactia. Nervous egotism is characterized by hyperexcitability and tremors, which may progress to clonic convulsions upon induced stress and excitement.
Production of Ergot Alkaloids
Published in Nduka Okafor, Benedict C. Okeke, Modern Industrial Microbiology and Biotechnology, 2017
Nduka Okafor, Benedict C. Okeke
The ergot alkaloids are so called because they were originally derived from ergot, a sclerotium (twisted mat of fungal hyphae) formed as a disease on the grain of rye (Secale cereale L.), a temperate cereal. The dried ergot is known among pharmacists as secale cornutum. The cause of the rye disease is a fungus, namely the ascomycete Claviceps purpurea. As will be seen later, ergot contains several (more than 40) highly potent alkaloids and the unwitting consumption of grain attacked by fungi producing ergot alkaloid has led to ‘ergotism’ (previously known as ‘Holy fire’ or ‘St. Anthony’s fire’ when it was not understood), a disease characterized by convulsions among other symptoms. Ingestion of contaminated grain, most often after the grain has been made into bread, causes ergotism, also known as the ‘Devil’s curse’, and has been a problem for centuries. It has been noted in writings from China as early as 1100 B.C. and in Assyria in 600 B.C.
Bacilli as sources of agrobiotechnology: recent advances and future directions
Published in Green Chemistry Letters and Reviews, 2021
Zerihun T. Dame, Mahfuz Rahman, Tofazzal Islam
Mycotoxins are toxic secondary metabolites produced by various filamentous fungi. They have medical and veterinary importance. The toxins consist of low molecular weight fungal metabolites. Fungi of the genera Aspergillus, Fusarium, and Penicillium are responsible for the production of most mycotoxins reported (104). Bennett (105) describes mycotoxins as natural products that trigger a toxic response in animals, plants, and microorganisms. At present, hundreds of them have been identified and investigated from various fungal species. One of the highly toxic groups of mycotoxins is aflatoxins, which are produced by Aspergillus spp. The Aspergillus infects wheat, walnut, corn, cotton, peanuts, and tree nuts. Consumption of aflatoxin-contaminated food for a while leads to health complications. Liver cancer, a decline in the immune system, malnutrition, and retarded child growth are some of the health impacts caused by aflatoxin consumptions (106). Acute toxicity can lead to liver failure and subsequent death associated with the ingestion of higher amounts of aflatoxin through contaminated foods (107, 108). Other groups of mycotoxins such as ochratoxins, fumonisins, deoxynivalenol, patulin, zearalenone (ZEA), and trichothecenes have also been associated with acute or chronic toxicity. Moreover, they are ubiquitous and pose a significant threat to human and animal health (109). Ringot et al. (110) argued that ochratoxin A (OTA) as one of the most harmful metabolites produced by toxigenic fungi has the potential to contaminate products such as cereals, figs, grapes, spices, coffee beans, cocoa beans, pork meat and dried vine fruits. According to Peraica et al. (111) mycotoxicosis has been a threat for millennia basically from the consumption of contaminated food. Few examples, ’St. Anthony’s fire’ caused by toxins from the ergot fungus, Claviceps purpurea, the 1891 cardiac beriberi in Japan, and alimentary toxic aleukia (characterized by nausea, vomiting, diarrhea, leukopenia, hemorrhaging, skin inflammation, and sometimes death) was another example of mycotoxicosis outbreak that occurred during the World War II in Russia and associated with the Fusarium toxin T-2. In addition to the health impact of mycotoxins on humans and animals, they account for a loss of about a quarter of global crop productions leading to the loss of billions of dollars.